1. Field of the Invention
The present invention relates to a connecting mechanism for a scan carriage and an axial rod, and particularly to a connecting mechanism applied in a multi-function printer (MFP) where the scan carriage leans tightly against and slides on the axial rod.
2. Description of the Prior Art
FIG. 1 illustrates an optical pick up and transformation device, which is usually mounted in a platform optical scanner or a multi-function printer with the same function, and is commonly called a scan carriage. The scan carriage 9 moves along an axial rod 92 for picking up an image of a scanned document. The scan carriage 9 mainly provides a linear light source 91 which moves linearly along the axial rod 92 and simultaneously emits light upon a document disposed on a glass. The scan carriage 9 also has a reflector, a lens, and an optical-electric transformation device, which is usually a charge coupled device (CCD). The reflected light is received through the lens of the scan carriage 9 by the reflector, and then is focused on the optical-electric transformation device to transform the scanned image data into electrical signals.
To achieve the purpose of sliding, the conventional scan carriage 9 is formed with a pair of pivoting portions 94. Each of the pivoting portions 94 is formed with an axial hole 96, and a sleeve 98 is mounted in the axial hole 96. The axial rod 92 is mounted slidably in the sleeve 98 for achieving linear movement. However, the above-mentioned structure has some disadvantages, which are described as follows:
1. An assembly tolerance between the axial hole 96 and the sleeve 98 of the scan carriage 9 must be highly precise matched tolerance, and there is a problem of concentricity after assembled the axial rod 92. The manufacturing thereof is very difficult.
2. The sleeve 98 and the axial rod 92 must maintain a clearance therebetween for assembly. However, the clearance will cause the scan carriage 9 to shake while moving and accumulate dust, which is detrimental for picking up an image.
Therefore, the optical picking up and transformation device of the prior art still has some inconvenience and disadvantages to be improved. The inventor, after investigation and research, thus provides the present invention of logical design for improving the above-mentioned imperfections.